Blender Solidify for rc plane wing
The acute angle in the trailing edge of the wing will result in the even thicknesses overlapping, I think the surest solution is a bit of remodeling.


Detach the faces constituting the outside of the trailing edge, P separate to a new object
Delete the appropriate inner faces of the rest of the wing, and fill the hole, to prepare to solidify the rest of the wing independently of the trailing edge
Solidify and apply the modifier
Recreate the hole for the trailing edge
Ctrl JRejoin the trailing  edge and the wing, Remove Doubles, tidy up.




This example treatment of your wing passes basic Manifold checks.